How to clean gasket mating surfaces

Post by **FireFox31** » 09 Jun 2023, 09:37

What's the best way to clean mating surfaces which have a flat gasket between them before replacing the gasket? I'm specifically interested in the intake manifold to engine block because I think my gasket isn't making a perfect seal, causing a major air and oil leak. I'm also interested in how to clean the coolant pump to engine block since a lot of that gasket was stuck to the block. What other flat gaskets need both mating parts to be perfectly clean before replacing the gasket? Thanks for your input.

Post by **scot850** » 09 Jun 2023, 10:21

Abscate suggested brake cleaner when I was doing the water pump on the 850. Spray it and let it sit for 30 mins, re-spray and using a plastic scraper off it came. Only hard part was around the 2 locator pins. I also stuffed a cloth or paper towel in the hole behind the water pump to prevent dirt and fluid getting into the coolant system.

Worked very well for me.

Neil.

Post by **BlackBart** » 09 Jun 2023, 11:31

^^^ All right on. Put some rags in the intake ports. Never use a steel scraper on aluminum. It doesn't have to be shiny aluminum clean, it has to be a smooth plane so the gasket can do it's job.

Post by **volvolugnut** » 09 Jun 2023, 11:40

Brake cleaner will remove almost anything. Just wear gloves and don't inhale it. For easier jobs where you want to remove oils use alcohol.
volvolugnut

Post by **foggydogg** » 10 Jun 2023, 06:46

If it's stubborn acetone or GoofOff
Carb cleaner works too, but evolves off pretty quickly, so spray and scrape tout de suite
These are less likely to gouge aluminum:
www.amazon.com/Plastic-Scraper-Cleaning ... r=1-5&th=1
I like the single edge because you can use them without the holder for tight spots.

Post by **FireFox31** » 30 Jun 2023, 15:20

I removed my air intake on one of my 2000 V70s. The engine block had aluminum corrosion around some of the ports. Scraping it with a plastic scraper did little to smooth out that corrosion. I assume the recommendation of brake cleaner was for gaskets stuck to surfaces because it also did nothing to the corrosion.

What's a good way to remove this rock hard aluminum corrosion? Perhaps ultra fine sandpaper? I think I sanded my other car's intake ports and now it has a gross air leak which I've yet to investigate.

I simply installed the intake over a minimally rough surface. I'll use a smoke machine to check it at some point.

Post by **volvolugnut** » 30 Jun 2023, 15:49

I have used tooth paste as a mild abrasive rubbed with a tooth brush or brass brush. It shines up aluminum nicely. Alcohol also cleans some gunk when brushed with a brass brush. I would avoid sandpaper unless you use a sanding block to help keep things flat.
volvolugnut

Post by **abscate** » 01 Jul 2023, 02:51

The gasket will seal that up, but your light sanding idea is fine too. Permatex would help but that gets messy

Post by **FireFox31** » 12 Sep 2023, 17:22

What's a good way to clean mating surfaces which don't have a gasket between them? I'm asking specifically about the thermostat top to housing connection. No gasket to smooth things out. Thanks.

Post by **abscate** » 12 Sep 2023, 18:12

The gasket rides around the edge of the thermostat in thst case. You need to get the groove and edge where thst gadkets sits smooth and shiny. A blunt screwdriver works well